A magneto-optical recording disk stores information on a thin film of magneto-optical material. This magneto-optical material is disposed between two protective layers. The protective layers are disposed so that the magneto-optical material is enclosed to protect it against corrosion. Surrounding the protective layers are the substrate layers which are typically made of glass or polymer to protect the disk against scratching or other surface damage. The surfaces of the substrate layers are scored with grooves at a substantially uniform depth of less than about a micron and spaced concentrically at intervals on the order of about one or two microns. A disk read/write head, which is positioned closely above the surface of the disk, emits a laser beam. Using this beam, the head tracks the grooves at a high speed and high accuracy while reading and writing data on the magneto-optical material.
For magneto-optical disks which have read/write heads that come in contact with the disk surface, lubricants are typically disposed on the surface of the disk to protect the disk head and disk surface from damage. These lubricants reduce friction between the disk head and disk surface, and they enhance the wear resistance of the disk surface and of the head.
Organic lubricants, such as fatty acid esters and perfluoropolyesters, have been used as lubricants on magnetic media. However, these lubricants, when applied by current methods, do not work well on magneto-optical disks. Organic lubricants suitable for magnetic disks, when disposed on magneto-optical disks, can accumulate in the grooves. This accumulated lubricant can interfere with the laser beam by causing a low signal to noise ratio while the disk head is reading and writing on a disk. If the lubricant is a liquid, capillary action can occur upon contact between the lubricant on the disk surface and the disk head at a low rate of spin of the disk. Additionally, degradation of the lubricants over time leads to buildup of sludged material. Further, liquid lubricant is depleted from sections of the surface as a result of migration over the surface of the substrate from centrifugal forces.
Thus, a need exists for a method for providing a lubricant on magneto-optical media in a manner which overcomes or minimizes the above mentioned problems.